Japanese Patent Application Laid-Open Publication No. 2013-59190 (Patent Document 1) discloses a power semiconductor module in which a SiC (silicon carbide)-MOSFET which is a wide band gap semiconductor switching element and a Si-IGBT are connected in parallel, of which a chip area of the former is configured to be smaller than that of the latter.
Patent Document 1 also discloses a gate driving circuit of the power semiconductor module.
However, Patent Document 1 only explains how to set the turn-on and turn-off timings of the parallel elements of the above gate driving circuit.
In some cases, the optimum driving voltage is different between the SiC-MOSFET and the Si-IGBT, however, this fact is not mentioned in Patent Document 1, and driving voltages of both are set to be equal.
For example, an on-voltage for the SiC-MOSFET may be set higher than that of the Si-IGBT in order to take advantage of the characteristic that the on-resistance is low.
Further, since a threshold voltage of the SiC-MOSFET is low, an off-voltage may be set to a negative potential to prevent erroneous turn-on in an off state.
Therefore, in a case of using the gate driving circuit disclosed in Patent Document 1, it is impossible to sufficiently obtain a loss reduction effect obtained by driving the SiC-MOSFET and the Si-IGBT in parallel.
In addition, if the gate driving circuits corresponding respectively to the SiC-MOSFET and the Si-IGBT are prepared, a respective dedicated drive IC is required so that a mounting area on a circuit board is increased and the cost is increased.